Hi Chris,
From what i understand, reversing the airflow doesn't give any improvement.
In your situation it is important to find out where the air comes from, that you are sucking in your radiator.
Cool wind from the front or hot air from below your engine bay!
I took care that the engine bay shrouds are all mounted to seal of the engine bay, so no hot air could comes back in the air flow.
( The setup i use is very simple, just the improved copper main radiator and additional Abarth radiator between the rear wheels, air flow as normally used, blowing the hot air out of the engine bay. I don't use an oil cooler. ) Oh forgotten i did replace the round thing ( don't know the word in English ) the fan belt is driving on, so the fan turns faster.
As i suggested before i would have the main radiator checked and the element replaced by a slightly bigger copper one, togehter with the additional radiator you use, it should work fine. Of course when you stop the temperature should raise a bit.
I have no experience with electrical fans, but i can image this works better, driving slowly. Besides this you loose less horsepower because you miss the belt driving the fan.
So it could be a few things causing your problem.
Good luck, best regards, Vincent.